The majority of new-ish master planned suburban communities I’ve seen do have walking paths, bikeways, and parks baked in. Usually with some large HOA maintained pool, theater, I’ve even seen man made beaches (100s of miles from a coast). Although, they still usually have fenced yards and cutting through someone’s fenced yard without explicit permission is highly frowned upon, I would actually say dangerous when combined with gun situation being what it is.

There’s a development in the works near me that is I think more along the lines of what the OP is thinking. A developer assembled around 1000 acres of farmland and proposes to build housing with half the land being open space. There are no amenities planned, however the houses will be grouped into “dense” clusters with paths through and around them. The paths will count as open space and are going to be owned by our county forest preserve agency, who will be building and maintaining that part.

The interesting part is that the agreement is that the county will be buying about 400 contiguous acres and then the housing clusters will be placed in 500 of the remaining 600 acres, with the 100 acres weaving in and out donated once they do the platting. They’re pretty far along in the process, with zoning and approvals in place. There are still a few unresolved technical issues that could derail the whole thing, yet we are less than one month away from signing the agreement that will irrevocably force them to sell the 400 acres. I’m excited to reach that milestone and after that won’t care at all if the project falls through (the remaining land revert to agriculture zoning and a future developer has to start over from the very beginning).

These are often designed by people that don't ever walk anywhere.